import React, { Component } from 'react'

export class A extends Component {
  render() {
    return (
      <h1>A{this.props.a}</h1>
    )
  }
}

export class B extends Component {
  //  Bref = React.createRef()
  constructor(props){
    super(props)
    console.log(this.props)
  }
  render() {
    return (
      <h1 ref={this.props.forwardRef}>B{this.props.b}</h1>
    )
  }
}

